With a scaling down of a semiconductor device, a mobility of a silicon channel may not meet a requirement of a continuous increase of a device performance. Therefore, it has become a focus to use other materials with the high mobility instead of silicon as a channel material or to introduce a strain engineering to increase the mobility of the channel.
Compound semiconductor materials such as Group III-V semiconductor materials have attracted a lot of attention due to their high mobility. Since the Si material has a scale effect in cost control and wafer size, a feasible method is to heteroepitaxially form the compound semiconductor materials on a Si wafer. However, due to a lattice mismatch between different materials, many dislocation defects may be introduced during an epitaxy, thus affecting a performance of a device.
Therefore, there is a need for a semiconductor device and a method for forming the same, in which the semiconductor device comprises a high-quality compound semiconductor layer with a low dislocation density and a low surface roughness formed on the Si wafer.